Unsaturated hydrocarbons such as α-olefins are an industrially important group of molecules which can serve as precursors for lubricants and surfactants in addition to being used in fuels, or as feedstock for further chemical conversion to e.g. fuels, polymers, plastics, textiles, solvents, adhesives, etc.
α-Olefins, more particularly linear α-olefins, have traditionally been produced from petroleum sources through oligomerization of ethylene but it would be advantageous to find alternative methods for producing such α-olefins, notably from renewable resources. Moreover, the chemical synthesis results in a mixture of linear α-olefins which exhibit different carbon chain length. Such mixture may not be desired as feedstock for further chemical conversion such as the production of poly-α-olefins of interest.
Microbial production of olefins has been reported. Examples include a three-gene cluster responsible for generating alkenes with internal double bonds through the head-to-head condensation of two fatty acyl-coenzyme A (acyl-CoA) molecules in Micrococcus luteus (Beller et al. 2010 Appl Environ Microbiol 76:1212-1223); a unique P450 decarboxylase OleTJE from Jeotgalicoccus sp. ATCC 8456, which directly decarboxylates C12 to C20 free fatty acids to form α-olefins in presence of H2O2 (WO 2009/085278, Rude et al. 2011 Appl Environ Microbiol 77:1718-1727, Liu et al. 2014 Biotechnology for Biofuels 7:28); another enzyme of the cyp152 P450 enzyme family, namely P450BSβ from Bacillus subtilis subsp. subtilis str. 168, for which decarboxylase activity on palmitic acid has been shown (WO 2009/085278, Rude et al. 2011); and a type I polyketide synthase from Synechococcus sp. PCC 7002, which is capable of transforming fatty acyl-ACPs into α-olefins via sequential polyketide synthase chain elongation, keto reduction, sulfonation mediated by its sulfotransferase domain, and the coupled hydrolysis and decarboxylation catalyzed by the thioesterase domain (Mendez-Perez et al. 2011 Appl Environ Microbiol 77:4264-4267).
In general, there is a need for alternative production methods of α-olefins, and more particularly improved processes that allow production of α-olefins at a lower cost and/or that are more environmental friendly. It is also desired to provide production methods which allow tailoring of the carbon chain length of the α-olefins, more particularly a production method for medium-chain α-olefins (i.e. α-olefins having a carbon chain length comprised between 7 and 13), more particularly for C11α-olefins.